In lightweight construction, in particular in aircraft construction and in aerospace, fiber-reinforced composite components, which have a high weight-saving potential on account of their high strength with at the same time low mass, are increasingly being used for load-bearing structural components.
The alignment of the reinforcing fibers in the finished composite component has a decisive influence on the achievable rigidity and strength. The reinforcing fibers should, as far as possible, follow the direction of loading, not have any wave formations and be subjected to uniform loading.
One possible way of complying with a requirement for a layer of fibers in accordance with loading is the so-called TFP process (“Tailored Fiber Placement”). This involves the laying of at least one fiber strand along any desired path curve and fixing of it on a backing layer with the aid of at least one attaching thread, whereby the position and orientation of the individual reinforcing fibers in a fiber preform that is formed in this way can be adapted in a virtually ideal way to the flux of force prevailing in the later composite component.
The production of the fiber preforms in the TFP process is performed on known devices, in particular on modern, computer-controlled automatic sewing and embroidering machines. Devices of this type for carrying out the TFP process generally have a stationary sewing head. Only the backing layer in which the fiber preform is formed by laying and attaching the fiber strands can be positioned in the spatial xy direction.
The fiber preform formed in this way may be impregnated with a curable polymer material or a resin system that can be cured by crosslinking, for example by means of the RTM process (“Resin Transfer Moulding”), to form a finished composite component.
A disadvantage of the known devices for carrying out the TFP process is that the fiber strand is only guided and laid in one plane, for example the xy plane. As a result, the fiber preform produced generally has a planar surface geometry. Only by further, downstream processing steps, for example re-forming, draping or the like, can the fiber preform be given a surface geometry that differs from the planar shape. However, the further processing of the initially planar fiber preform may cause undesired wave formations and displacements of the reinforcing fibers, so that the intended alignments of the reinforcing fibers in the fiber preform, in particular alignments oriented with the flux of force, are not achieved, or only partially.